We divide 664438 by 9
The aim is to understand the frequency of 9 in 664438.

On to step 1:
If we divide 6 by 9, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 9

Going ahead to step 2:
9 can be fit into 66 7 times, resulting in a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
If we subtract 63 from 66, we get 3.
Include the next digit (4) from the dividend after 3, then repeat: 34 / 9

On to step 3:
When dividing 34 by 9, we get 3 with a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 73.0
Subtract 27 from 34 to get 7.
Take the next digit (4) from the dividend and append it to 7, then repeat: 74 / 9

Going ahead to step 4:
If we divide 74 by 9, we get 8 and a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 738.0
Subtracting 72 from 74 leaves us with 2.
Take the next digit (3) from the dividend and append it to 2, then repeat: 23 / 9

Moving on to step 5:
If we divide 23 by 9, we get 2 and a remainder of 5.
Put 2 as the next digit of the answer. 
Result so far: 7382.0
If we subtract 18 from 23, we get 5.
Bring next digit (8) of the dividend behind the 5 and repeat the process: 58 / 9

Going ahead to step 6:
When dividing 58 by 9, we get 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 73826.0
Subtract 54 from 58 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 7:
The number 9 fits into 40 4 times, leaving a remainder of 4.
The next digit of our result is 4. 
Result so far: 73826.4
Deduct 36 from 40 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 8:
If we divide 40 by 9, we get 4 and a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 73826.44
Subtracting 36 from 40 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final outcome is 73826.44, with a leftover of 0.004.